At Duncan & Groves we only use naturally durable hardwood such as opepe, ekki, greenheart, cumaru and robinia which is either reclaimed or from FSC certified sawmills. These species are physically hard and naturally durable.
Robinia is grown in commercial quantities in Europe. The trees are generally coppiced providing smaller fast grown sections. This limits the diameter and length of timber available but means it is ideal for providing fast growing sustainable hardwood for playgrounds.
Robinia is classed as highly durable with a life span in excess of 25 years in ground contact without chemical treatment. Ekki, Opepe, greenheart and cumaru are some of the most durable timber species known with a life spans in excess of 25 years in ground contact without chemical treatment. These species are also suitable for marine environments.
Timber is made up of 3 major layers; bark, sapwood and heartwood.
- The bark and sapwood are full of sugary starches and sap which attracts pests and forms rot. It is essential to remove these layers to help with the longevity of the equipment.
- The Heartwood is the only part we use for manufacturing. It has the highest quality properties, is durable, robust and does not require any treatment.